[libcxx] [test] Extend the UNSUPPORTED lines in strong_order_long_double.verify.cpp for non-x86_64 Windows

libcxx/test/std/language.support/cmp/cmp.alg/strong_order_long_double.verify.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // UNSUPPORTED: c++03, c++11, c++14, c++17
 
 // The following platforms have sizeof(long double) == sizeof(double), so this test doesn't apply to them.
 // This test does apply to aarch64 where Arm's AAPCS64 is followed. There they are different sizes.
 // UNSUPPORTED: target={{arm64|armv(7|8)(l|m)?|powerpc|powerpc64}}-{{.+}}
-// UNSUPPORTED: target=x86_64-pc-windows-{{.+}}
+// MSVC configurations have long double equal to regular double on all
+// architectures.
+// UNSUPPORTED: target={{.+}}-pc-windows-msvc
+// ARM/AArch64 MinGW also has got long double equal to regular double, just
+// like MSVC (thus match both MinGW and MSVC here, for those architectures).
+// UNSUPPORTED: target={{aarch64|armv7}}-{{.*}}-windows-{{.+}}
 
 // <compare>
 
 // template<class T> constexpr strong_ordering strong_order(const T& a, const T& b);
 
 // libc++ does not support strong_order(long double, long double) quite yet.
 // This test verifies the error message we give for that case.
 // TODO: remove this test once long double is properly supported.